Image generating device, static text detecting device and method thereof

ABSTRACT

An image generating device and a method thereof are disclosed in the present invention. The image generating device and method may find out true motion for static text strings. The image generating device and method detect static text angles from consecutive frames and use a 3D-static text filter to recover correct motion vector fields. After our Static Text Detector fixing, the static text strings like subtitles can get more accurate motion vector and improve video quality.

BACKGROUND OF THE INVENTION

(a) Field of the Invention

The invention relates to a frame rate up-conversion (FRC) technique,particularly to an image generating device with the function ofdetecting static texts and a method thereof.

(b) Description of the Related Art

The frame rate up-conversion (FRC) technique is used for increasing theframe rate of a video source and has been applied in various fields,such as low-bit network video transmission for bandwidth-saving,converting a video source with a frame rate of 25 Hz into a higher framerate for reducing frame juddering, and applying in hold-type liquidcrystal displays (LCD) for avoid frame blurring and achieving clearimage quality.

Most of the frame rate up-conversion (FRC) techniques use motionestimation (ME) to calculate the motion vector of an object and performmotion compensation interpolation (MCI) to allocate the moving object indifferent frames. Most of the motion estimation techniques use a blockmatching estimation algorithm to calculate the motion vector having theminimum of the sum of absolute difference (SAD). However, in manycircumstances, many motion estimation techniques are easily trapped inthe minimum of a local SAD, that is, the motion vector having theminimum of a local SAD is not necessary to be the real motion vector ofthe object and even the motion vector having the minimum of a global SADis not necessary to be the real motion vector of the object.

Furthermore, while the block matching estimation algorithm in the priorart is used to process estimation, the correct estimation for imagesignals including static texts, such as captions, signs, etc. cannot bemade when the background of the image contains moving object(s). Asshown in FIG. 1, the upper part of the figure shows a preceding frame F0and the lower part shows a current frame F1. For the preceding frame F0as an example, the label “T” indicates a static text and the label “B”indicates a background object, the label “Mv” indicates a motion vector.When the image changes from the frame F0 to F1, the block matchingestimation algorithm in the prior art will estimate an incorrect motionvector Mv due to the motion of the background object “B”. Such incorrectestimation often results in static text juddering or moving with themoving object to thereby lower the image displaying quality.

BRIEF SUMMARY OF THE INVENTION

In order to remove the static text juddering or moving problem in theimage, one object of the invention is to provide an image generatingdevice and a method thereof.

One embodiment of the invention provides an image generating device. Theimage generating device is to receive a current image and a precedingimage to generate at least one interpolated image. The image generatingdevice comprises a vector estimation circuit, a static text detectingcircuit, and a motion compensation interpolation circuit. The vectorestimation circuit performs block matching estimation on a target blockof the current image and a predetermined search block of the precedingimage to generate a temporary motion vector of the target block and aplurality of motion estimation errors corresponding to the target block.The static text detecting circuit receives the temporary motion vectorof the target block, the current image, and the preceding image todetect static texts of the current image and the preceding image, andthen corrects the temporary motion vector according to the result ofdetecting static texts to generate a corrected motion vector of thetarget block. The motion compensation interpolation circuit performsimage interpolation according to all the corrected motion vectors of thecurrent image, the current image, and the preceding image to generatethe at least one interpolated image.

One embodiment of the invention provides a static text detectingcircuit. The static text detecting circuit comprises a static text angledetecting circuit and a data filtering circuit. The static text angledetecting circuit receives a current image and a preceding image,divides the current and preceding images into the same number of blocks,separately detects the angle of each pixel in each block of the currentimage and the preceding image according to at least one angle, andcounts the number of the same angles of the pixels in each block of thecurrent image and the corresponding block of the preceding image. Thedata filtering circuit determines the number of effective angles in eachblock of the current image and the preceding image according to thenumber of the same angles, and compares the number of effective anglesin each block with a predetermined value to decide whether the blockcomprises any static text or not so as to generate static text flag dataas a reference for image motion vector correction.

One embodiment of the invention provides a method for generating animage, comprising the following steps: at first, receiving a precedingimage and a current image and performing motion vector estimation onthese two frames, the current image and the preceding image; performingstatic text detection on these two images; determining whether the blockand the corresponding block in these two images comprise all or part ofstatic texts or not; if yes, setting the motion vector of the blockcomprising static texts to zero; if not, setting the motion vector ofthe block comprising no static text to its original vector; and thenperforming image interpolation on the preceding image and the currentimage according to the corrected motion vector to generate at least oneinterpolated image.

Other purposes and advantages of the invention can be understood by thefollowing disclosed technical characteristics of the invention.Accompanying with the following figures, examples and claims, the aboveand other objectives and advantages of the invention will be describedin detail in the following.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a schematic diagram illustrating an example of static textsand a background object in a frame.

FIG. 2A shows a structure block diagram illustrating the imagegenerating device according to one embodiment of the invention.

FIG. 2B shows a structure block diagram illustrating the vectorestimation circuit according to one embodiment of the invention.

FIG. 3A shows a structure block diagram illustrating the static textdetecting circuit according to one embodiment of the invention.

FIG. 3B shows a structure block diagram illustrating the static textangle detecting circuit according to one embodiment of the invention.

FIG. 3C shows a schematic diagram illustrating the initial static textflag data and the filtered static text flag data according to oneembodiment of the invention.

FIG. 3D shows a structure block diagram illustrating the data filteringcircuit according to one embodiment of the invention.

FIG. 4 shows a schematic diagram illustrating an example of static textsand a background object in a frame according to the invention.

FIG. 5 shows a structure block diagram illustrating the data filteringcircuit according to one embodiment of the invention.

FIG. 6 shows a flow chart illustrating the method for image generationaccording to one embodiment of the invention.

DETAILED DESCRIPTION OF THE INVENTION

The following describes several preferred embodiments of the inventions,such as various electric circuits, elements, and related methods. Thosewho are skilled in the art should understand that the invention can beimplemented by various methods, not limited by the following embodimentsor characteristics in the embodiments. The well-known details will notbe repeatedly described to avoid distracting the attention from the keypoint of the invention.

Furthermore, the image inputted into the image generating deviceaccording to the invention may be a frame or a field. The followingexamples are described by using a frame.

FIG. 2A shows a structure block diagram illustrating the imagegenerating device according to one embodiment of the invention.Referring to FIG. 2A, the image generating device 200 according to theinvention comprises a vector estimation circuit 210, a static textdetecting circuit 300, and a motion compensation interpolation circuit220. The static text detecting circuit 300 may be an N-dimensionalstatic text detecting circuit where N is a positive integer and lessthan infinity. For example, it may be a 3D-static text detectingcircuit.

As shown in FIG. 2A and FIG. 2B, the vector estimation circuit 210receives a current frame F1 and a preceding frame F0, divides thecurrent frame F1 and the preceding frame F0 into the same number ofblocks, and compares a target block with a predetermined search block ofthe preceding frame F0 to calculate a plurality of motion estimationerrors. The vector estimation circuit 210 compares these motionestimation errors to acquire the temporary motion vector TMV_(i) of thetarget block and a plurality of motion estimation errors correspondingto the target block. Then, after processing the whole frame by repeatingthe above operation, all the temporary motion vectors TMV, outputted bythe vector estimation circuit 210 are shown in FIG. 2B.

In the above, the temporary motion vector TMV_(i) of the target blockmay be the motion vector having the minimum motion estimation error. Itshould be noted that the invention is not limited to the above example.In another embodiment, a target block may be compared with apredetermined search block of the current frame F1 to calculate aplurality of motion estimation errors and thus to acquire the temporarymotion vector TMV, of the target block.

The above motion estimation errors may be acquired by variousalgorithms, such as SAD (sum of absolute difference) algorithm, MAD(mean absolute difference) algorithm, MSE (mean square error) algorithm,or the current or future algorithm. The following embodiment uses theSAD value calculated by the SAD algorithm as the motion estimationerror. Thus, a plurality of SAD values calculated by the vectorestimation circuit 210 form a SAD curve and then the magnitude of theSAD curve corresponds to the size of the above predetermined searchblock. Those who are skilled in the art should understand that there arevarious methods to calculate the temporary motion vector TMV_(i). Itsfurther details will not be given hereinafter.

As shown in FIG. 2A, the vector estimation circuit 210 transmits thetemporary motion vector TMV, of the target block to the static textdetecting circuit 300.

The static text detecting circuit 300 receives the temporary motionvector TMV_(i) of each target block, and performs static text detectionand motion vector correction on the frames F0 and F1 to generate thecorrected motion vector MMV_(i) of each target block.

After the motion compensation interpolation circuit 220 sequentiallyreceives all the corrected motion vectors MMV_(i) of the current block,the motion compensation interpolation circuit 220 performs imageinterpolation according to the current frame F1 and the preceding frameF0 to thereby generate at least one interpolated frame.

FIG. 3A shows a structure block diagram illustrating the static textdetecting circuit 300 according to one embodiment of the invention. Thestatic text detecting circuit 300 comprises a static text angledetecting circuit 310 and a data filtering circuit 320. The static textangle detecting circuit 310 receives a current frame F1 and a precedingframe F0, divides the current frame F1 and the preceding frame F0 intothe same number of blocks. The number of divided blocks of the frame isthe same as the number of blocks divided by the vector estimationcircuit 210. Then, the static text angle detecting circuit 310separately detects the angle of each pixel in each block of each frameaccording to at least one angle and counts the number of the same anglesof the pixels in each block of the frame F1 and the corresponding blockof the frame F0. The data filtering circuit 320 determines the number ofeffective angles in each block of the frames F0 and F1 according to thenumber of the same angles, and compares the number of effective anglesin each block with a first predetermined value to decide whether theblock comprises any static text or not.

For a static text the two pixels at the same position in the frame F0and the frame F1 have the same angle while for a moving object only oneof the two pixels at the same position in the frame F0 and the frame F1has an angle and the other pixel does not have an angle. Therefore, whenthe number of effective angles in each block is larger than the firstpredetermined value, the block indeed has an angle and thus the blockhas static text(s). According to this information, the temporary motionvector TMV_(i) in each target block can be corrected. For example, whena block comprises static text(s), the temporary motion vector TMV_(i) ofthe block is set to zero so as to generate the corrected motion vectorMMV_(i). On the contrary, when a block comprises no static text, thetemporary motion vector TMV_(i) of the block is not changed and thevalue of the temporary motion vector TMV_(i) is treated as the correctedmotion vector.

FIG. 3B shows a structure block diagram illustrating the static textangle detecting circuit 310 according to one embodiment of theinvention. The static text angle detecting circuit 310 comprises a firststatic text angle detecting unit 310 a and a second static text angledetecting unit 310 b. The first static text angle detecting unit 310 adetects at least one angle of each block in the preceding frame F0. Forexample, as shown in FIG. 3B, the first static text angle detecting unit310 a comprises 8 sets of angle detecting units for detecting if eachblock in the preceding frame F0 has these 8 sets of angles: +0, −0, +90,−90, +45, −45, +135, −135 degrees. Certainly, the invention is notlimited to this example. In another embodiment, N sets of angles aredetected where N is a positive integer less than infinity. The secondstatic text angle detecting unit 310 b also comprises 8 sets of angledetecting units for detecting if each block in the current frame F1 hasthese 8 sets of angles. The number of detected angles of the two statictext angle detecting units 310 a and 310 b is substantially the same.

At first, the first static text angle detecting unit 310 a is used as anexample for illustration.

The first static text angle detecting unit 310 a receives the precedingframe F0 and executes the matrix operation to perform angle detection oneach block of the preceding frame F0. For example, the predeterminedvalue 30 for determining existence of an angle is assumed. Then,calculating if a block has +0 degree in the preceding frame F0 may beprocessed as follows: the pixel value of a block in preceding frame F0,for example,

$\left\lbrack {\left. \quad\begin{matrix}40 & 40 & 40 \\40 & 40 & 40 \\0 & 0 & 0\end{matrix} \right\rbrack,} \right.$

multiplied by the testing matrix of +0 degree,

$\left\lbrack {\left. \quad\begin{matrix}1 & 1 & 1 \\0 & 0 & 0 \\{- 1} & {- 1} & {- 1}\end{matrix} \right\rbrack,} \right.$

is 40*1+40*1+40*1+40*0+40*0+40*0+0*(−1)+0*(−1)+0*(−1)=120. The result ofthis calculation is 120, that is larger than 30, and thus this block has+0 degree. Assuming that the pixel value of the corresponding block inthe current frame F1 is

$\left\lbrack {\left. \quad\begin{matrix}40 & 40 & 40 \\40 & 40 & 40 \\0 & 0 & 0\end{matrix} \right\rbrack,} \right.$

similarly the testing matrix of +0 degree,

$\left\lbrack {\left. \quad\begin{matrix}1 & 1 & 1 \\0 & 0 & 0 \\{- 1} & {- 1} & {- 1}\end{matrix} \right\rbrack,} \right.$

is used to test and the same value 120 is obtained, that is also largerthan 30. Therefore, the same block in the two frames has an angle of +0degree. Thus, the direction counter (not shown in the figure) providedin the static text detecting circuit is added by one.

For other angles of each block in the two frames, the following matrixesmay be used in operations. Based on the above description, those who areskilled in the art should understand how to calculate the angles thateach block has. If the values calculated by the total of three sets ofangles in the above 8 sets of angles of a block are larger than theabove predetermined value, 30, the value of the direction counter of theblock is 3. It should be noted that the matrix or predetermined valuefor the invention is not limited to this example. In another example,various N*M matrixes may be used and the predetermined value may be Xwhere N, M, X are positive integers less than infinity.

The following shows the matrixes for 8 sets of angles:

${{{testing}\mspace{14mu} {matrix}\mspace{14mu} {of}}\mspace{14mu} + {0\mspace{14mu} {{degree}\mspace{14mu}\begin{bmatrix}1 & 1 & 1 \\0 & 0 & 0 \\{- 1} & {- 1} & {- 1}\end{bmatrix}}}};$${{{testing}\mspace{14mu} {matrix}\mspace{14mu} {of}}\mspace{14mu} - {0\mspace{14mu} {{degree}\mspace{14mu}\begin{bmatrix}{- 1} & {- 1} & {- 1} \\0 & 0 & 0 \\1 & 1 & 1\end{bmatrix}}}};$${{{testing}\mspace{14mu} {matrix}\mspace{14mu} {of}}\mspace{14mu} + {90\mspace{14mu} {{degrees}\mspace{14mu}\begin{bmatrix}1 & 0 & {- 1} \\1 & 0 & {- 1} \\1 & 0 & {- 1}\end{bmatrix}}}};$${{{testing}\mspace{14mu} {matrix}\mspace{14mu} {of}}\mspace{14mu} - {90\mspace{14mu} {{degrees}\mspace{14mu}\begin{bmatrix}{- 1} & 0 & 1 \\{- 1} & 0 & 1 \\{- 1} & 0 & 1\end{bmatrix}}}};$${{{testing}\mspace{14mu} {matrix}\mspace{14mu} {of}}\mspace{14mu} + {45\mspace{14mu} {{degrees}\mspace{14mu}\begin{bmatrix}1 & 1 & 0 \\1 & 0 & {- 1} \\0 & {- 1} & {- 1}\end{bmatrix}}}};$${{{testing}\mspace{14mu} {matrix}\mspace{14mu} {of}}\mspace{14mu} - {45\mspace{14mu} {{degrees}\mspace{14mu}\begin{bmatrix}{- 1} & {- 1} & 0 \\{- 1} & 0 & 1 \\0 & 1 & 1\end{bmatrix}}}};$${{{testing}\mspace{14mu} {matrix}\mspace{14mu} {of}}\mspace{14mu} + {135\mspace{14mu} {{degrees}\mspace{14mu}\begin{bmatrix}0 & 1 & 1 \\{- 1} & 0 & 1 \\{- 1} & {- 1} & 0\end{bmatrix}}}};{and}$${{testing}\mspace{14mu} {matrix}\mspace{14mu} {of}}\mspace{14mu} - {135\mspace{14mu} {{{degrees}\mspace{14mu}\begin{bmatrix}0 & {- 1} & {- 1} \\1 & 0 & {- 1} \\1 & 1 & 0\end{bmatrix}}.}}$

It should be noted that the matrix operation is as follows: taking +0degree as an example,

${\begin{bmatrix}{{P\; 11},} & {{P\; 12},} & {P\; 13} \\{{P\; 21},} & {{P\; 22},} & {P\; 23} \\{{P\; 31},} & {{P\; 32},} & {P\; 33}\end{bmatrix}\begin{bmatrix}1 & 1 & 1 \\0 & 0 & 0 \\{- 1} & {- 1} & {- 1}\end{bmatrix}} = {{{P\; 11} \star 1} + {{P\; 12} \star 1} + {{P\; 13} \star 1} + {{P\; 21} \star 0} + {{P\; 22} \star 0} + {{P\; 23} \star 0} + {{P\; 31} \star \left( {- 1} \right)} + {{P\; 32} \star \left( {- 1} \right)} + {{P\; 33} \star {\left( {- 1} \right).}}}$

Those who are skilled in the art should understand that the above matrixoperation is only an example and the operation on different types ofmatrixes can be deduced by analogy.

Besides, when the background of the current frame F1 moves down, thepixel value of a block in the preceding frame F0 is

$\left\lbrack {\left. \quad\begin{matrix}40 & 40 & 40 \\40 & 40 & 40 \\0 & 0 & 0\end{matrix} \right\rbrack,} \right.$

and the pixel value of the corresponding block in the current frame F1is

$\left\lbrack {\left. \quad\begin{matrix}40 & 40 & 40 \\40 & 40 & 40 \\40 & 40 & 40\end{matrix} \right\rbrack.} \right.$

If the matrix of +0 degree is used in matrix operation, the operationvalue of the block of the preceding frame F0 is 120 while the operationvalue of the block of the current frame F1 is 0. Thus, the pixel in thisblock has no +0 degree. The value of the direction counter is unchanged.

The values of a plurality of direction counters of each pixel in eachblock can be calculated by repeating the above operation on the pixelvalue, that is, the number of pixels having +0 degree in this block canbe acquired. The number of pixels having other angles −0, +90, −90, +45,−45, +135, −135 degrees can be also acquired. Therefore, there are 8counting values from 8 direction counters. If the counting value islarger than the second predetermined value, the angle is an effectiveangle and the angle counter is added by one. Thus, the number ofeffective angles of each block can be acquired. For example, assumingthe 8 counting values of the 8 direction counters are “0, 3, 0, 6, 22,12, 0, 0” for a block and the second predetermined value is set to 10,there are two counting values larger than 10. Thus, the value of theangle counter is 2, that is, there are 2 effective angles in this block.By repeating the above steps, the number of effective anglescorresponding to each block in the frame shown on the left hand side ofFIG. 3C can be acquired, that is, the initial static text flag data.

In FIG. 3C, the initial static text flag data of the frame is shown onthe left hand side of the figure where the value “0” indicates the blockdoes not have any effective angle, the value “1” indicates the block hasone effective angle, the value “2” indicates the block has two effectiveangles, and the value “3” indicates the block has three effectiveangles, and so on. The data shown in the figure is the initial statictext flag data D of the static text angle detecting circuit 310.

FIG. 3D shows a structure block diagram illustrating the data filteringcircuit 320 according to one embodiment of the invention. The datafiltering circuit 320 comprises an erosion unit 320 a and a dilationunit 320 b. The data filtering circuit 320 receives the initial statictext flag data D and the initial static text flag data D undergoes anerosion process by the erosion unit 320 a and then undergoes a dilationprocess by the dilation unit 320 b so that the filtered static text flagdata D′ is generated. The erosion process of the erosion unit 320 a isthat, for example, referring to FIG. 3C, the surrounding blocks of theblock b1 have no angle and thus the erosion unit 320 a determines theweight of the block b1 is lower based on the predetermined weightingrule to thereby change the block b1 from 1 to 0. The other higher value3 or 2 in the block may be changed to 1 by the erosion unit 320 a forunified processing. The dilation process of the dilation unit 320 b isthat, for example, the block b2 is changed from 0 to 1. Although theblock b2 is 0, the surrounding blocks of the block b2 have angles andthus the dilation unit 320 b determines the weight of the block b2 ishigher based on the predetermined weighting rule to thereby change theblock b2 from 0 to 1. By repeating the above steps, the value of eachblock of the filtered static text flag data D′ shown on the right handside of the figure can be acquired. These values are the static textflags. According to the above description, those who are skilled in theart should understand how to acquire the filtered static text flag dataD′ shown on the right hand side of the figure. Thus, its further detailswill not be given hereinafter.

In one embodiment, the weighting rule of the above erosion unit 320 acomprises:

1. eroding a block while this block has a total of one angle and thesurrounding blocks of this block do not comprise a plurality of anglesand setting the text flag of this block to false; and/or

2. eroding a block while the sum of the total number of angles of thesurrounding blocks of this block is less than a predetermined value andsetting the text flag of this block to false.

In one embodiment, the weighting rule of the above dilation unit 320 bcomprises:

1. dilating a block while the blocks on the left and right of this blockhave a plurality of angles and setting the text flag of this block totrue; and/or

2. dilating a block while the blocks on the top and bottom of this blockhave a plurality of angles and setting the text flag of this block totrue; and/or

3. dilating a block while the sum of the total number of blocks having aplurality of angles surrounding the block is more than a predeterminedvalue and setting the text flag of this block to true; and/or

4. dilating a block while the sum of the total number of angles of thesurrounding blocks of this block is more than a predetermined value andsetting the text flag of this block to true.

The invention is not limited to the above example and other current orfuture weighting rules may be used.

In FIG. 3C, for the value in the frame shown on the right hand side ofthe figure, the block having a value of 1 indicates the block comprisesall or part of static texts. According to these static text flags, thestatic text detecting circuit 300 processes the temporary motion vectorof each corresponding static text flag. In one embodiment, the statictext detecting circuit 300 corrects the temporary motion vectorsaccording to these corresponding static text flags to generate thecorrected motion vectors to the motion compensation interpolationcircuit. For example, as the value of the flag of a block is 1, itindicates the block comprises static text(s). Then, the static textdetecting circuit 300 changes the value of the temporary motion vectorcorresponding to this block to 0 and generates a corrected motion vectorsupplied to the motion compensation interpolation circuit 220 as areference for frame interpolation. On the contrary, as the value of theflag of a block is 0, it indicates the block comprises no static text.Thus, the value of the temporary motion vector corresponding to thisblock is unchanged and used as the value of the corrected motion vectorto be outputted to the motion compensation interpolation circuit 220 asa reference for frame interpolation.

Following the above steps, the motion compensation interpolation circuit220 acquires the correct motion vector of each block and then correctlycalculates at least one interpolated frame based on the preceding frameF0 and the current frame F1 so that the static texts keep unmoving whilethe background B in the image is moving, as shown in FIG. 4. Therefore,the problem of static text juddering or moving due to incorrect motionvectors in the prior art can be solved so that the image quality can beenhanced.

Moreover, as shown in FIG. 5, the data filtering circuit 320 furthercomprises a temporal storage 320 c for storing and detecting thefiltered static text flags of a plurality of frames. While the filteredstatic text flags of Z consecutive frames are all the same, the temporalstorage 320 c determining that the filtered static text flags arecorrect for the static text detecting circuit 300 to perform motionvector correction where the value Z is more than 1 and less thaninfinity. If the flag of one of the frames is different, the static textflag will not be used and the static text detection on the frame will bereprocessed. Therefore, the accuracy in detecting static texts becomeshigher.

FIG. 6 shows a flow chart illustrating the method for generating animage according to one embodiment of the invention.

Step S602: start;

Step 5604: receiving a preceding frame and a current frame andperforming motion vector estimation on these two frames where each frameis divided into a plurality of blocks and the number of blocks and thesize of each block of the two frames are the same;

Step S606: performing static text detection on these two frames;

Step S608: determining whether the block and the corresponding block inthese two images comprise all or part of static texts or not; if yes, goto Step S610; if not, go to Step S612;

Step S610: setting the motion vector of the block comprising statictexts to zero;

Step S612: setting the motion vector of the block comprising no statictext to its original vector;

Step S614: performing image interpolation on the preceding frame and thecurrent frame based on the corrected motion vector to generate at leastone interpolated image;

Step S616: end.

Although the present invention has been fully described by the aboveembodiments, the embodiments should not constitute the limitation of thescope of the invention. Various modifications or changes can be made bythose who are skilled in the art without deviating from the spirit ofthe invention.

1. An image generating device, comprising: a vector estimation circuit,for performing block matching estimation according to a target block ofa first image and a predetermined search block of a second image togenerate a temporary motion vector of the target block; a static textdetecting circuit, for receiving the temporary motion vector of thetarget block, the first image, and the second image to detect statictexts of the first image and the second image and then correcting thetemporary motion vector according to the result of detecting statictexts to generate a corrected motion vector of the target block; and amotion compensation interpolation circuit, for performing imageinterpolation according to all the corrected motion vectors of the firstimage, the first image, and the second image to generate at least oneinterpolated image.
 2. The device according to claim 1, wherein thestatic text detecting circuit comprises: a static text angle detectingcircuit, for separately detecting the angle of each pixel in each blockof the first image and the second image according to at least one angle,and counting the number of pixels having the same angles in each blockof the first image and the corresponding block of the second image so asto determine the weight of each block; and a data filtering circuit, fordetermining whether a block comprises any static text or not accordingto the weight of the block.
 3. The device according to claim 1, whereinthe static text detecting circuit comprises: a static text angledetecting circuit, for separately detecting the angle of each pixel ineach block of the first image and the second image according to at leastone angle, and counting the number of the same angles of the pixels ineach block of the first image and the corresponding block of the secondimage so that the weight of each block is determined according to thenumber of the same angles in the block; and a data filtering circuit,for determining whether a block comprises any static text or notaccording to the weight of the block.
 4. The device according to claim3, wherein a block having a relatively large weight is determined tocomprise static texts while a block having a relatively small weight isdetermined to comprise no static text, or a block comprising more anglesindicates the weight of the block is larger while a block comprisingfewer angles indicates the weight of the block is smaller.
 5. The deviceaccording to claim 2, wherein the static text detecting circuitcomprises: a first static text angle detecting unit comprising N sets ofangle detecting units for detecting whether each block of the secondimage has the N sets of angles or not; and a second static text angledetecting unit comprising N sets of angle detecting units for detectingwhether each block of the first image has the N sets of angles or notwherein N is a positive integer less than infinity; wherein the totalnumber of angles included in each block of the second image and thefirst image is calculated according to the detection result from thefirst and the second static text angle detecting units and is convertedto initial static text weight data.
 6. The device according to claim 5,wherein the data filtering circuit comprises: an erosion unit, forreceiving the initial static text weight data and eroding the blockhaving a relatively small weight in the initial static text weight dataaccording to a predetermined weighting rule to generate filtered statictext flag data; and a dilation unit, for receiving the initial statictext weight data and dilating the block having a relatively large weightin the initial static text weight data according to a predeterminedweighting rule to generate the filtered static text flag data.
 7. Thedevice according to claim 4, wherein the weighting rule of the erosionunit comprises: eroding a block while the block has a total of one angleand the surrounding blocks of the block do not comprise a plurality ofangles and setting the text flag of the block to false; and/or eroding ablock while the sum of the total number of angles in the surroundingblocks of the block is less than a predetermined value and setting thetext flag of the block to false.
 8. The device according to claim 4,wherein the weighting rule of the dilation unit comprises: dilating ablock while the blocks on the left and right of this block have aplurality of angles and setting the text flag of this block to true;and/or dilating a block while the blocks on the top and bottom of thisblock have a plurality of angles and setting the text flag of this blockto true; and/or dilating a block while the number of blocks having aplurality of angles surrounding this block is more than a predeterminedvalue and setting the text flag of this block to true; and/or dilating ablock while the sum of the total number of angles in the surroundingblocks of this block is more than a predetermined value and setting thetext flag of this block to true.
 9. The device according to claim 6,wherein the static text detecting circuit corrects the temporary motionvector according to the filtered static text flag data to generate thecorrected motion vector of the target block.
 10. The device according toclaim 6, wherein the data filtering circuit further comprises: atemporal storage, for storing and detecting the filtered static textflags of a plurality of images and, while the filtered static text flagsof Z consecutive images are all the same, determining that the filteredstatic text flags are correct for the static text detecting circuit toperform motion vector correction where Z is more than 1 and less thaninfinity.
 11. The device according to claim 1, wherein the first imageand the second image are divided into the same number of blocks, or thetemporary motion vector of the target block is the motion vector havingthe minimum motion estimation error.
 12. A method for generating animage, comprising: receiving a second image and a first image andperforming motion vector estimation on the first image and the secondimage; performing static text detection on these two images; determiningwhether the block and the corresponding block in these two imagescomprise all or part of static texts or not; if yes, setting the motionvector of the block comprising static texts to zero; if not, setting themotion vector of the block comprising no static text to its originalvector; performing image interpolation on the second image and the firstimage according to the corrected motion vector to generate at least oneinterpolated image.
 13. The method according to claim 12, wherein eachimage is divided into a plurality of blocks, the size of each block isthe same, and the number of blocks in each image is the same, or thefirst image and the second image are fields or frames.
 14. A static textdetecting circuit, comprising: a static text angle detecting circuit,for separately detecting the angle of each pixel in each block of thefirst image and the second image from at least one angle and countingthe number of the same angles of the pixels in each block of the firstimage and the corresponding block of the second image so that the weightof each block is determined according to the number of the same anglesin the block; and a data filtering circuit, for determining whether ablock comprises any static text or not according to the weight of theblock.
 15. The device according to claim 14, wherein a block having arelatively large weight is determined to comprise static texts while ablock having a relatively small weight is determined to comprise nostatic text or a block comprising more angles indicates the weight ofthe block is larger while a block comprising fewer angles indicates theweight of the block is smaller.
 16. The device according to claim 14,wherein the static text detecting circuit comprises: a first static textangle detecting unit comprising N sets of angle detecting units fordetecting whether each block of the second image has the N sets ofangles or not; a second static text angle detecting unit comprising Nsets of angle detecting units for detecting whether each block of thefirst image has the N sets of angles or not wherein N is a positiveinteger less than infinity; wherein the total number of angles includedin each block of the second image and the first image is calculatedaccording to the detection result from the first and the second statictext detecting units and is converted to initial static text weightdata.
 17. The device according to claim 14, wherein the data filteringcircuit comprises: an erosion unit, for receiving the initial statictext weight data and eroding the block having a relatively small weightin the initial static text weight data according to a predeterminedweighting rule to generate filtered static text flag data; and adilation unit, for receiving the initial static text weight data anddilating the block having a relatively large weight in the initialstatic text weight data according to a predetermined weighting rule togenerate the filtered static text flag data.
 18. The device according toclaim 17, wherein the weighting rule of the erosion unit comprises:eroding a block while this block has a total of one angle and thesurrounding blocks of this block do not comprise a plurality of anglesand setting the text flag of this block to false; and/or eroding a blockwhile the sum of the total number of angles of the surrounding blocks ofthis block is less than a predetermined value and setting the text flagof this block to false.
 19. The device according to claim 17, whereinthe weighting rule of the dilation unit comprises: dilating a blockwhile the blocks on the left and right of this block have a plurality ofangles and setting the text flag of this block to true; and/or dilatinga block while the blocks on the top and bottom of this block have aplurality of angles and setting the text flag of this block to true;and/or dilating a block while the number of blocks having a plurality ofangles surrounding this block is more than a predetermined value andsetting the text flag of this block to true; and/or dilating a blockwhile the sum of the total number of angles of the surrounding blocks ofthis block is more than a predetermined value and setting the text flagof this block to true.
 20. The device according to claim 14, wherein thedata filtering circuit further determining the number of effectiveangles in each block of the first image and the second image accordingto the number of the same angles, comparing the number of effectiveangles in each block with a predetermined value to decide whether theblock comprises any static text or not so as to generate static textflag data as a reference for image motion vector correction.
 21. Thedevice according to claim 20, wherein the static text angle detectingcircuit comprises: a first static text angle detecting unit comprising Nsets of angle detecting units for detecting whether each block of thesecond image has the N sets of angles or not; a second static text angledetecting unit comprising N sets of angle detecting units for detectingwhether each block of the first image has the N sets of angles or notwherein N is a positive integer less than infinity; wherein the initialstatic text flag data of the second image and the first image iscalculated according to the detection results from the first and thesecond static text angle detecting units.
 22. The device according toclaim 20, wherein the data filtering circuit comprises: an erosion unit,for receiving the initial static text flags and eroding the static textflag in the initial static text flag data according to a predeterminedweighting rule to generate filtered static text flag data; and adilation unit, for receiving the initial static text flag data anddilating the static text flag in the initial static text flag dataaccording to a predetermined weighting rule to generate the filteredstatic text flag data.
 23. The device according to claim 22, wherein thedata filtering circuit further comprises: a temporal storage, forcounting the filtered static text flags of a plurality of images and,while the filtered static text flags of Z consecutive images are all thesame, determining that the filtered static text flags are correct forthe static text detecting circuit to perform motion vector correctionwhere Z is more than 1 and less than infinity.